The use of MR elements as sensors for reading magnetically recorded data is well known. However, MR sensors are sensitive to thermal noise, among other things. To reduce thermal noise problems, MR sensor elements have been deposited, or otherwise mounted, on silicon substrates or similar material disposed in magnetic head assemblies. Silicon is easy to fabricate and provides good heat conduction. However, magnetoresistive heads with silicon substrates have been found to be subject to excessive wear when used for scanning magnetic media which is contaminated with particulates.